In a motor described in Patent Literature 1, slits extending from a radially outer side of magnet insertion holes toward an outer peripheral surface of a rotor are formed in core regions of the rotor, which are located on a radially outer side of permanent magnets, so that a stator magnetic flux in a q-axis phase is hardly linked with the core regions located on the radially outer side of the permanent magnets to reduce unbalance in rotor magnetic attraction force, thereby reducing vibration and noise.
Further, in the motor, each of the permanent magnets to be built in the rotor is formed so as to have an arc-like cross section, while each of the permanent magnets is arranged in a rotor core so that a convex portion side is oriented toward a radially inner side.
Through the arrangement described above, the area of surfaces of the magnets can be designed to be large to increase a magnetic flux generated by the permanent magnets so as to increase a driving torque of the motor. In this manner, downsizing can be achieved or drive efficiency can be improved.